Gas separator for submersible pump



J. T- CARLE GAS SEPARATOR FOR SUBMERSIBLE PUMP Dec. 13, 1966 Filed Nov.12, 1964 jnverzirr -fi5 vk I Caz r'ze ,2 9% w @m United States PatentOflice 329L057 Patented Dec. 13, 1966 GAS EPARATOR FOR SUBMERSIBLE PUMPJoseph T. (Iarle, Tulsa, (Okla, assiguor to Borg-Warner Corporation, acorporation of Illinois Filed Nov. 12, 1964, Ser. No. 410,637 14 Claims.((11. 103113) This invention relates to gas separtors. Moreparticularly, it relates to a gas separator for a submersible motor pumpassembly of the type used in oil and water wells.

It has long been a practice to utilize a submersible motor pump assemblydisposed within a well casing of an oil or water well to pump well fluidfrom the well. In many such applications, substantial quantities ofgaseous substances are present in the well which adversely affect thepumping operation if allowed to enter the impeller portion of the pump.In extreme situations, excessive quantities of gas have caused the pumpto gas lock, completely restricting the flow of well fluid. For thisreason, it has been found desirable to provide the pump unit with a gasseparator adapted to remove the gaseous substances from the fluid beingpumped to insure efflcient and continuous operation of the motor pumpassembly.

An example of such a gas separator is shown in U.S. patent applicationNo. 311,937 filed September 24, 1963, by Joseph T. Carle, entitled, GasSeparator, which is a continuation of application No. 132,167 filedAugust 17, 1961, now Patent 3,175,501.

The gas separator disclosed in the above-mentioned application isadapted to be positioned between a submersible motor unit andsubmersible pump unit in surrounding relation to an interconnectingdrive shaft which is operable by the motor. The pump unit is positionedabove the motor unit and includes a downwardly directed impeller inletof annular cross section surrounding the drive shaft.

The gas separator includes an elongated housing extending downwardlyfrom the pump unit which is divided into an outer annular chamberadjacent the housing and an inner annular chamber adjacent the driveshaft by an inner sleeve or flow tube extending downwardly from the pumpinlet. The housing is closed at the bottom to form a reservoir, and thehousing includes inlet openings at its upper end to allow entry of wellfluid into the housing above the reservoir.

A separator pump is provided at the bottom of the reservoir whichincludes a gas separator impeller secured to and driven by the driveshaft. The gas separator impeller is of the axial inflow-radial outflowtype and includes an upwardly directed inlet adjacent the drive shaftand a radially directed outlet disposed in spaced relation to thehousing wall. A cross-over housing is provided within the separatorhousing which is adapted to direct well fluid from the outer reservoirdefining chamber to the gas separator impeller inlet and from the gasseparator impeller outlet to the inner annular chamber whichcommunicates with the inlet of the motor pump assembly along the driveshaft.

In the gas separator described, well fluid enters the reservoir chamberthrough the openings in the top of the housing and passes downwardlythrough the reservoir chamber and cross-over housing into the upwardlydirected gas separator pump impeller inlet adjacent the drive shaft. Thefluid is pumped radially outwardly and returned by way of the cross-overhousing to the inner annular chamber defined by the flow tube and driveshaft. The well fluid travels upwardly in this inner annular chamberinto the pump impeller inlet.

Movement of well fluid in the manner described effects removal ofentrained gas in several ways. First, gas is separated from the wellfluid as it enters the openings in the separator housing. Further, thereservoir is adapted to retain sufiicient quantities of well fluid toallow gas which may enter to bubble off before the fluid enters theseparator pump. Additionally, as the fluid passes through the separatorpump, it is caused to reverse direction, further effecting separation ofentrained gas.

In addition to the above, the gas separator of the previously mentionedapplication is particularly adopted to recover from a gas surge orpump-off condition wherein substantial quantities of gas are present inthe well which curtail pumping of well fluid existing within the well.The separator pump impeller inlet is upwardly directed and thereforenatural gravity flow causes well fluid to enter the impeller of theseparator pump from the reservoir chamber. Thus, when the gas surge hasterminated, well fluid naturally flows into the gas separator impellerinlet for transfer to the pump inlet. The cross-over housing whichincludes the gas separator impeller is vented to insure displacement ofentrapped gas as the well fluid enters the inlet of the cross-over fromthe chamber reservoir.

Separators of the type described have generally proven to besatisfactory. However, in certain instances, it has been found thatquantities of gas have entered the reservoir chamber through the inletopenings in the separator housing Wall, and it has further been foundthat in certain instances quantities of gas have succeeded in travellingthrough the separator pump and into the inner chamber defined by theflow tube and shaft.

Accordingly, it is the principal object of the present invention toprovide an improved form of gas separator for a submersible motor-pumpassembly.

Another object of the present invention is to provide a gas separatorfor a submersible pump which includes a portion adapted to momentarilyretain quantities of well fluid in a generally quiescent conditionisolated from the gas-fluid mixture in the well to allow entrained gasto bubble off prior to entry of the fluid into the separator reservoir.

A related object of the present invention is to provide a gas separatorfor a submersible motor pump which includes a series of retention cupsadapted to momentarily retain quantities of well fluid in a quiescentcondition to allow entrained or occluded gas to bubble off prior to theentry of the well fluid into the separator reservoir.

It is a further object of the present invention to provide a gasseparator for a submersible motor pump which includes a plurality ofretention cups having a relatively small discharge area as compared toinlet area so as to providea controlled rate of discharge of well fluidinto the separator reservoir to effect temporary retention of quantitiesof the well fluid within the cup to allow release of entrained gas.

It is a still further object of the present invention to provide a gasseparator for a submersible motor pump which includes a plurality ofretention cups adapted to direct well fluid into the separator reservoirwhich have inlet openings disposed in elevated relation to dischargeopenings so as to prevent inadvertent entry of gaseous substances risingwithin the annular space between the separator and the well casing.

It is still a further object of the present invention to provide a gasseparator for a submersible pump which is adapted to effect removal ofgas from the inner annular chamber of the separator defined by the motorpump drive shaft and the cross-over flow tube.

These and other objects of the invention will become apparent withreference to the following description and the accompanying drawing.

In the drawing:

FIGURE 1 is a front elevational sectional view of a gas separatorincorporating various of the features of the invention;

FIGURE 2 is a transverse sectional view taken along the line 22 ofFIGURE 1;

FIGURE 3 is a transverse sectional view taken along line 33 of FIGURE 1;

FIGURE 4 is a longitudinal sectional view of a portion of the apparatusshown in FIGURE 1 showing various other features of the invention.

In an illustrated embodiment of the invention shown in the drawing, agas separator generally designated G is disposed within a well definedby a casing C. The separator G is coaxially aligned with and interposedbetween a generally cylindrical submersible motor M and a generallycylindrical submersible well pump P, both of which are shownschematically in FIGURE 1. The motor M is disposed below the pump withinthe casing C and is operatively connected to the pump by a generallyvertical drive shaft which includes a portion S extending through thegas separator. The motor M may be provided with an integrally formedsubmersible seal unit which surrounds the drive shaft S and which isadapted to prevent the entry of well fluid into the motor. Alternativelya separate generally cylindrical seal unit U as shown schematically inFIGURE 1 may be used.

Very generally the gas separator G of the illustrated embodimentincludes an elongated separator housing 11 disposed in surroundingrelation to the drive shaft S, which includes splines 13 at each end forconnection with cooperating segments (not shown) of the drive shaftassociated with the motor M and pump P. The separator housing is dividedinto an outer reservoir chamber 15 adapted to initially receive fluidfrom the well through a series of inlets in the housing, and an innerflow chamber 17 which is in communication with the motor pump P andadapted to supply it with generally gas free well fluid for subsequentpumping from the well. This division is effected by a flow tube 19extending longitudinally intermediate the shaft S and separator housing11.

A separator pump 21 including an impeller 23 operable by the drive shaftS and a cross-over housing 25 is disposed adjacent the bottom of theseparator housing 11. Operation of the impeller 23 effects transfer ofwell fluid fromthe outer reservoir chamber 15 to the inner annularchamber 17 through the cross-over housing 25.

A series of spaced apart open-ended retention cups 27 are disposed insurrounding relation to the separator housing 11 adjacent the well fluidinlets and define with the housing a series of annular retentionchambers 29 which initially receive the well fluid.

The chambers so formed include generally cylindrical inlet areas whichare relatively larger than the inlets into the reservoir chamber 15 thusproviding a controlled rate of discharge of fluid into the reservoirchamber. Additionally the retention chambers 29 are of suflicientcapacity to effect momentary retention of well fluid isolated from theturbulent gas-fluid mixture existing in the well by virtue of thecontrolled discharge rate so as to allow entrained gas to bubble olfprior to entry of the well fluid into the reservoir chamber.

Also, the inlets to the retention chambers defined by the retention cupsare disposed in elevated relation to the inlets to the reservoir chamber15 thus preventing gas bubbling upwardly within the well casing C frominadvertently entering the separator housing and impairing pumpoperation.

In addition to the above, a bleed-off tube 31 is provided whichcommunicates between the inner annular chamber 17 and the well definedby the casing C. This bleedoff tube allows escape of such gas as mayhave passed through the retention cup chambers 29, reservoir chamber 15and separator pump 21 and entered the flow tube so as to effectivelyprevent the gas from travelling into the pump P.

More specifically, and as best seen in FIGURE 1, the elongated separatorhousing 11 is of generally cylindrical configuration and is disposedcoaxially with respect to the rotatable drive shaft S to form the outerwall of the outer reservoir chamber 15.

The separator housing 11 includes a lower reservoir defining portion 33having a diameter smaller than the well casing so as to allow for theflow of well fluid therebetween. The reservoir defining portion isclosed at the bottom by nipple 35 secured thereto as by cooperatingthreaded portions 37. The nipple extends radially inwardly intorotatable sealing engagement with the shaft S. A flange 39 is providedon the nipple 35 for connect on of the separator to the seal unit U.

The separator housing 11 further includes an upper portion defined by agenerally vertically extending cylindrical support tube 41 having adiameter smaller than the lower portion 33. The support tube 41 and thelower reservoir defining portion 33 are connected by an annular spacerring 43 which includes a series of radially directed threaded aperatures45 including set screws 47 in contact with the flow tube 19 and adaptedto maintain the relative spaced apart relation between the separatorhousing 11 and the flow tube 19.

The support tube 41 includes a plurality of rows of generallyhorizontally elongated slots 49 disposed at predetermined verticallyspaced intervals about the cylindrical surface of the support tube whichform the inlet openings into the annular reservoir chamber 15, to allowentry of well fluid. A sufiicient number of rows of slotsare provided soas to insure adequate flow of well fluid into the reservoir chamberduring the pumping operation.

An upper end 51 of the support tube 41 is closed by a nipple 53 whichincludes a depending sleeve 55 which extends into the end 51 of thetube. The nipple 53 further includes a cylindrical bore surrounding thedrive shaft S which forms therewith an annular inlet passageway 57 todirect flowing well fluid to the pump P. The nipple is provided with acounter bore 59 adapted to be engaged by a co-acting member (not shown)formed on the pump P to effect communication between the pump inlet andthe inlet passageway 57.

As best seen in FIGURE 1, the flow tube 19 which. divides the separatorhousing 11 into an outer reservoir chamber 15 and an inner annularchamber 17 is secured to the nipple 53 as by threads 61 and dependstherefrom in coaxial aligned relation to the drive shaft S andtheseparator housing 11. The shaft S is supported within the flow tube19 by a plurality of spider bearing 63 which include radially directedspaced apart ribs 65 (best seen in FIGURE 3) which allow for the passageof fluid through the inner flow chamber 17.

The flow tube 19 is connected to the lower reservoir defining portion 33of the separator housing 11 by a gen-- erally conical cross-over support67 which includes angularly directed opening 69 to allow passage of wellfluid. The cross-over support 67 is secured to the flow tube: 19 as bythreads 71 at a point spaced from a lower .end 73 of the tube and to thelower portion 33 of the separator housing 11 by threads 75. By thisarrangement the flow tube provides a structural connection between theupper nipple 53 and the lower nipple 35 enabling the gas separator tosupport the motor M and seal unit U which are secured to the flange 39of the nipple 35. It should be appreciated however that other portionsof the structure could be used as supporting members, such as, forexample, the separator housing 11 could be so constructed as to providethe necessary structural rigidity.

The lower end 73 of the flow tube 19 is connected to the cross-overhousing 25 of the separator pump 21 located at the bottom of theseparator housing 11 as best seen in FIGURE 1, the cross-over housingincludes an upwardly directed flange 77 which telescopically receivesthe end 73 of the flow tube 19. An 0 ring seal 79 is interposed betweenthem to effect a liquid tight seal.

The cross-over housing 25 includes a series of circumferentiallydisposed alternately directed passages 81 and 83 which communicaterespectively between the outer reservoir chamber 15 and a separator pumpinlet 85 formed Within the housing adjacent the drive shaft S andbetween the inner annular chamber 17 and a separator pump discharge area87 formed within the housing adjacent the separator housing 11. Thecross-over housing 25 is secured to the lower reservoir defining portion33 of the separator housing 11 as by a set screw 89 to prevent rotationduring operation of the separator pump 21.

The separator pump impeller 23 is disposed within the cross-over housing25 and is secured to an rotatable with the drive shaft S. The impelleris of the axial in-flow and radial out-flow type, and includes anupwardly directed inlet eye 91 adapted to receive well fluid from theinlet area 85.

Operation of the pump efiects movement of the well fluid from thereservoir chamber 15 to the inlet 85 through the passageway 81. Thefluid then passes through the impeller 23 to the discharge area 87 andis directed to the inner flow chamber 17 by the passages 83. Thus areversal of flow takes place within the separator pump, and since theimpeller eye 91 is upwardly directed natural gravity flow of well fluidfrom the reservoir chamber 15 tends to fill the cross-over housingpassage 81 to supply fluid to the gas separator impeller for pumping. Tofacilitate such gravitational flow when well fluid becomes availableafter a gas surge or a pumped off condition wherein the separatorhousing becomes filled with gas, a bleeder passage 93 is provided whichextends between the separator pump impeller 23 and the well through thenipple 35 to allow gas to be displaced by the incoming liquid.

Referring now particularly to FIGURES l and 3, the retention cups 27forming retention chambers 29 which initially receive well fluid priorto entry of the fluid into the reservoir chamber 15 are disposed insurrounding relation to the support tube 41 in overlying relation to theinlet slots 49.

Each of the retention cups 27 is associated with one of the rows ofslots 49 in the support tube 41 and includes an outer cylindrical wall95 having a diameter approximating the outer diameter of the reservoirdefining portion 33 of the separator housing 11. A converging portion 97extends from a lower end of the cylindrical wall radially inwardly, andterminates in an inner cylindrical bore 99 disposed immediately adjacentand below the row of slots 49 with which it is associated thus formingwith the support tube the retention chamber 29.

The lower most retention cup 27 is supported by the annular spacer ring43 which connects the flow tube 19 to the reservoir defining portion 33.The lower most row of slots 49, therefore, must be located apredetermined distance from the annular ring 43 to insure properrelative positioning of the cups 27 with respect to the slots 49. Toplace the retention cups in position upon the support tube 41, the uppernipple 53 is removed from the flow tube 19 at the threads 61.

The longitudinal length of the retention cups 27 is less than thelongitudinal distance between the rows of slots 49 and the cups aremaintained in spaced apart relation by spacer ribs 101 which depend fromthe under side of the converging portion 97 and engage the cylindricalwall 95 of the next preceeding cup. The spacing so provided creates aseries of generally cylindrical inlet areas 103 between adjacentretention cups which allow entry of well fluid into the retentionchambers 29 defined by the cylindrical walls 95 and converging portions97 and the support tube 41. These inlet areas 103 are larger than,

and consequently of greater capacity than, the area of the associatedrow of inlet slots 49, in the support tube 41. Also, as the inner bore99 of the cups surround the support tube 41 immediately below the rowsof inlet slots 49, the inlet areas 103 are disposed in elevated relationto the slots 49 of each row requiring a generally downward flow of fluidin the retention chambers 29.

The retention cups 29 therefore, form quiescent areas for momentaryretention of well fluid isolated from the turbulent gas-well fluidmixture within the casing C allowing entrained gas to bubble ofi priorto entry of well fluid into the reservoir chamber 15.

Further, as the inlet areas 103 to the retention c-hambers 29 defined bythe spaced relationship between successive retention cup 27 are elevatedwith respect to the respective rows of slots 49 in the support tube 41,gas bubbling upwardly within the well is precluded from inadvertent-lyentering the reservoir chamber.

Additionally the inlet areas 103 are larger than the discharge area;defined by the particular row of slots 49 in the support tube 41 withwhich a particular retention cup is associated. The discharge rate ofwell fluid from the retention chambers 29 into the reservoir chamber istherefore controlled, further effecting momentary delay of fluid flowenabling entrained gas to bubble off prior to entry of the fluid intothe reservoir chamber 15. A sufficient number of rows of retention cups27 and slots 49 are provided to insure an adequate supply of well flui-dto the reservoir chamber during operation of the motor M and pump P.

Though the retention cups 27 of the illustrated embodiment have beendescribed as separate elements stacked upon one another and retained inspaced relationship by the depending ribs 101, it must be appreciatedthat a variety of configurations may be utilized without departing fromthe scope of the invention. For example, retention cups may be weldeddirectly to the support tube in the proper location with respect to therows of slots 49, or alternately, a support tube similar to the tube 41may be provided with integrally formed retention cups extendingoutwardly therefrom. In addition, the exact configuration of theretention cup may vary, within the purport of the invention disclosed.In this regard, upwardly directed genera-11y conical shaped cups may beused or cups having cylindrical outer walls and horizontally disposedflanges extending inwardly into contact with the support tube 41 mayalso be utilized so long as they provide the necessary cup capacity forretention and momentary delay of fluid flow.

Referring again specifically to FIGURE 1, the bleed-off tube 31 isdisposed adjacent the upper end of the drive shaft S and includes anopen end 105 disposed in close proximity to the drive shaft. Thebleed-off tube extends radially outwardly through appropriately formedapertures in the support tube 41 and nipple 53 into communication withthe well. It has been found that entrained gases which pass through thegas separator and enter the flow chamber 17 are caused to accumulateadjacent the drive shaft S by virtue of the centrifugal force impartedby the separator pump 21. As the accumulated gas travels along the driveshaft S to the motor pump inlet 57, it is intercepted at the inner end105 of the bleed-off tube 31 and, due to the pressure differentialexisting between the fluid in the flow chamber 17 and the fluid in thewell casing C the gas is caused to be exhausted back into the well, thuspreventing entry of the gas into the pump inlet 57.

As can be seen, an improved gas separator has been provided whicheffectively causes momentary delay of well fluid being pumped, in aquiescent area isolated from the well turbulence to enable entrained gasto bubble off and return to the well prior to entry of the fluid intothe separator reservoir. Additionally, well fluid entering the gasseparator is caused to initially flow downwardly in the retentionchambers thus preventing inadvertent entry of bubbling gas movingupwardly in the well. Further, accumulated gas within the flow chamberof the separator which is directly connected to the pump inlet iseffectively removed by the provision of a bleed-off tube extending fromthe flow chamber to the well.

While the terms upward and downward and inwardly and outwardly have beenused in the illustrated embodiment of the invention, it must beappreciated that these terms are only relative and not restrictive ofthe inventive concept illustrated.

Various of the features of the invention have been particularly shownand described, however, it should be obvious to one skilled in the artthat various modification may be made therein without departing from thescope of the invention.

We claim:

1. In a gas separator for a submersible well pump which separatorincludes, a gas separator housing defining a reservoir chamber andadapted for disposition within a well in operative association, with asubmersed pump; means within the housing defining a passageway adaptedto provide fluid communication between the reservoir chamber and thepump, and means defining at least one inlet opening in the housingadapted to provide fluid communication between the well and thereservoir chamber; means defining a retention chamber disposed inoverlying relation to said inlet opening, said chamber defining meansincluding means defining an inlet adapted to initially receive the fluidfrom the well, and said retention chamber having a fluid retainingcapacity suflicient to momentarily retain well fluid flowing from thewell to the reservoir chamber, said retention chamber defining meansbeing disposed so as to permit entrained gas to escape from the fluid insaid retention chamber through said inlet and return to the well.

2. In a gas separator for a submersible well pump which separatorincludes, a gas separator housing defining a reservoir chamber andadapted for disposition within a well in operative association with asubmersed pump, means within the housing defining a passageway adaptedto provide fluid communication between the reservoir chamber and thepump, and means defining at least one inlet opening in the housingadapted to provide fluid communication between the well and thereservoir chamber; means defining a retention chamber disposed inoverlying relation to said inlet opening, said chamber defining meansincluding means defining an inlet adapted to initially receive the fluidfrom the well which is larger than the inlet opening in the housing soas to control the rate of fluid flow through said retention chamber intothe reservoir, and said retention chamber having a fluid retainingcapacity suflicient to momentarily retain well fluid flowing from thewell to the reservoir chamber so as to permit gas to escape from thefluid so retained and return to the well.

3. In a gas separator for a submersible well pump which separatorincludes, a gas separator housing defining a reservoir chamber andadapted for disposition within a well in operative association with asubmersed pump, means within the housing defining a passageway adaptedto provide fluid communication between the reservoir chamber and thepump, and means defining at least one inlet opening in the housingadapted to provide fluid communication between the well and thereservoir chamber; means defining a retention chamber disposed inoverlying relation to said inlet opening, said chamber defining meansincluding means defining an inlet adapted to initially receive the fluidfrom the well which inlet is disposed in elevated relation to the inletopening in the separator housing so as to effect downward movement offluid in said retention chamber from said retention chamber inlet to theinlet in the separator housing, and said retention chamber having afluid retaining capacity sufficient to momentarily retain well fluidflowing from the well to the reservoir chamber so as to permit entrainedgas to escape from the fluid so retained and return to the well.

4. In a gas separator for a submersible well pump which separatorincludes, a gas separator housing defining a reservoir chamber andadapted for disposition within a well in operative association with asubmersed pump, means within the housing defining a passageway adaptedto provide fluid communication between the reservoir chamber and thepump, and means defining at least one inlet opening in the housingadapted to provide fluid communication between the well and thereservoir chamber; means defining a retention chamber disposed inoverlying relation to said inlet opening, said chamber defining meansincluding means defining an inlet adapted to initially receive the fluidfrom the well, and said retention chamber having a fluid retainingcapacity sufficient to momentarily retain well fluid flowing from thewell to the reservoir chamber so as to permit entrained gas to escapefrom the fluid so retained and return to the well, and means defining aseparate passageway providing communication between the pumpcommunicating passageway and the exterior of said housing to allow gascontained therein to escape therefrom and return to the well.

5. In a gas separator for submersible well pump which separatorincludes, a gas separator housing defining a reservoir chamber andadapted for disposition within a well in operative association with asubmersed pump; means within the housing defining a passageway adaptedto provide fluid communication between the reservoir chamber and thepump, and means defining at least one inlet opening in the housingadapted to provide fluid communication between the well and thereservoir chamber; a retention cup disposed in overlying relation tosaid inlet opening including portions substantially in contact with saidhousing and portion spaced therefrom so as to form therewith a retentionchamber, a portion of said retention chamber defining an inlet adaptedto initially receive the fluid from the well, and said retention chamberhaving a fluid retaining capacity suflicient to momentarily retain wellfluid flowing from the well to the reservoir chamber so as to permitentrained gas to escape from the fluid so retained and return to thewell.

6. In a gas separator for a submersible well pump which separatorincludes, a generally cylindrical gas separator housing defining areservoir chamber and adapted for disposition within a well in operativeassociation with a submersed pump, means within the housing defining apassageway adapted to provide fluid communication between the reservoirchamber and the pump, and means defining at least one inlet opening inthe housing adapted to provide fluid communication between the well andthe reservoir chamber; a retention cup including a generally cylindricalportion having a diameter greater than the diameter of the separatorhousing disposed in surrounding relation to a portion of said housing inoverlying relation to said inlet opening to form a retention chamberthereover, said cylindrical portion further defining an inlet adapted toinitially receive the fluid from the well, and said retention chamberhaving a fluid retaining capacity sufiicient to momentarily retain wellfluid flowing from the well to the reservoir chamber, said retention cupbeing disposed so as to permit entrained gas to escape from said cupthrough said inlet and return to the well.

7. In a gas separator for a submersible well pump which separatorincludes, a generally cylindrical gas separator housing defining areservoir chamber and adapted for disposition within a well in operativeassociation with a submersed pump, means within the housing defining apassageway adapted to provide fluid communication between the reservoirchamber and the pump, and means defining at least one inlet opening inthe housing adapted to provide fluid communication between the well andthe reservoir chamber; a retention cup including a generally cylindricalportion having a diameter greater than the diameter of the separatorhousing disposed in surrounding relation to a portion of said housing inoverlying relation to said inlet opening to form a retention chamberthereover, said cylindrical portion further defining an inlet adapted toinitially receive the fluid from the well which inlet is larger than theinlet opening in the separator housing so as to control the rate offluid flow through said retention chamber into said reservoir, and saidretention chamber having a fluid retaining capacity suflicient tomomentarily retain well fluid flowing from the well to the reservoirchamber so as to permit entrained gas to escape from the fluid soretained and return to the well.

8. In a gas separator for a submersible well pump which separatorincludes, a generally cylindrical gas separator housing defining areservoir chamber and adapted for disposition within a well in operativeassociation with a submersed pump, means Within the housing defining apassageway adapted to provide fluid communication between the reservoirchamber and the pump, and means defining at least one inlet opening inthe housing adapted to provide fluid communication between the well andthe reservoir chamber; a retention cup including a generally cylindricalportion having a diameter greater than the diameter of the separatorhousing disposed in surrounding relation to a portion of said housing inoverlying relation to said inlet opening to form a retention ciamberthereover, said cylindrical portion further defining an inlet adapted toinitially receive the fluid from the well which inlet is disposed inelevated relation to the inlet opening in the separator housing so as toeffect generally downward movement of the fluid in said retentionchamber from said retention chamber inlet to the inlet in the separatorhousing, and said retention chamber having a fluid retaining capacitysumcient to momentarily retain well fluid flowing from the well to thereservoir chamber so as to permit entrained gas to escape from the fluidso retained and return to the well.

9. In a gas separator for a submersible well pump which separatorincludes, a generally cylindrical gas separator housing defining areservoir chamber and adapted for disposition within a well in operativeassociation with a submersed pump, means within the housing defining apassageway adapted to provide fluid communication between the reservoirchamber and the pump, means defining a plurality of circumferentiallydisposed longitudinally spaced apart rows of slots in said housingadapted to provide fluid communication between the well and thereservoir chamber; a plurality of longitudinally spaced apart retentioncups disposed in surrounding relation to said separator housing, each ofsaid retention cups being disposed in overlying relation to a row ofsaid slots and including a generally cylindrical portion having adiameter greater than the diameter of the separator housing so as toform a retention chamber thereover, the longitudinal spacing betweensuccessive cups providing inlet into said retention chambers adapted toinitially receive fluid from the well, said retention chambers having afluid retaining capacity suificient to momentarily retain well fluidflowing from the well to the reservoir chamber so as to permit entrainedgas to escape from the fluid so retained and return to the well.

10. In a gas separator for a submersible well pump which separatorincludes, a generally cylindrical gas separator housing defining areservoir chamber and adapted for disposition within a well in operativeassociation with a submersed pump, means within the housing defining apassageway adapted to provide fluid communication between the reservoirchamber and the pump, means defining a plurality of circumferentiallydisposed longitudinally spaced apart rows of slots in said housingadapted to provide fluid communication between the well and thereservoir chamber; a plurality of longitudinally spaced apart retentioncups disposed in surrounding relation to said separator housing, each ofsaid retention cups being disposed in overlying relation to a row ofsaid slots and including a generally cylindrical portion having adiameter greater than the diameter of the separator housing so as toform a retention chamber thereover, the longitudinal spacing betweensuccessive cups providing inlets into said retention chambers adapted toinitially receive fluid from the well, the inlets so formed being largerthan the inlets into the reservoir chamber through said row of slots soas to control the rate of fluid flow through said retention chambersinto the reservoir, said retention chambers having a fluid retainingcapacity suflicient to momentarily retain well fluid flowing from thewell to the reservoir chamber so as to permit entrained gas to escapefrom the fluid so retained and return to the well.

11. In a gas separator for a submersible well pump which separtorincludes, a generally cylindrical gas separator housing defining areservoir chamber and adapted for disposition within a well inoperativeassociation with a submersed pump, means within the housing defining apassageway adapted to provide fluid communication between the reservoirchamber and the pump, means defining a plurality of circumferentiallydisposed longitudinally spaced apart rows of slots in said housingadapted to provide fluid communication between the well and thereservoir chamber; a plurality of longitudinally spaced apart retentioncups disposed in surrounding relation to said separator housing, each ofsaid retention cups being disposed in overlying relation to a row ofsaid slots and including a generally cylindrical portion having adiameter greater than the diameter of the separator housing so as toform a retention chamber thereover, the longitudinal spacing betweensuccessive cups providing inlets to said retention chambers adapted toinitially receive fluid from the well, the inlets so formed beingdisposed in elevated relation to the respective inlet to said reservoirchamber from said retention chamber through said rows of slots so as toeffect generally downward movement of fluid in said retention chamberfrom said inlet to said slots, said retention chambers having a fluidretaining capacity suflicient to momentarily retain well fluid flowingfrom the well to the reservoir chamber so as to permit entrained gas toescape from the fluid so retained and return to the well.

12. In a gas separator for a submersible Well pump which separatorincludes, a generally cylindrical gas separator housing defining areservoir chamber and adapted for disposition within a well in operativeassociation with a submersed pump, means within the housing defining apassageway adapted to provide fluid communication between the reservoirchamber and the pump, means defining a plurality of circumferentiallydisposed longitudinally spaced apart rows of slots in said housingadapted to provide fluid communication between the well and thereservoir chamber; a plurality of longitudinally spaced apart retentioncups disposed in surrounding relation to said separator housing, each ofsaid retention cups being disposed in overlying relation to a row ofsaid slots and including a generally cylindrical portion having 21diameter greater than the diameter of the separator housing so as toform a retention chamber thereover, said retention cups being retainedin spaced apart relation by at least one depending rib formed thereonand engaging the cylindrical portion of the next succeeding cup, thelongitudinal spacing between successive cups providing inlets into saidretention chambers adapted to initially receive fluid from the well,said retention chambers having a fluid retaining capacity suflicient tomomentarily retain well fluid flowing from the well to the reservoirchamber so as to permit entrained gas to escape from the fluid soretained and return to the well.

13. A retention cup for a gas separator adapted to be disposed insurrounding relation to a cylindrical portion of a separator housing inoverlying relation to an inlet opening formed therein so as to form aretention chamber thereover comprising, a generally cylindrical portionhaving a diameter larger than the diameter of the cylindrical portion ofthe separator housing, means defining an aperture within said cupcoaxial with said cylindrical portion adapted to receive the cylindricalportion of the housing, a converging portion connecting said cylindricalportion and said aperture defining means.

14. A retention cup for a gas separator adapted to be disposed insurrounding relation to a cylindrical portion of a separator housing inoverlying relation to an inlet opening formed therein so as to form aretention chamber thereover comprising, a generally cylindrical portionhaving a diameter larger than the diameter of the cylindrical portion ofthe separator housing, means defining an aperture Within said cupcoaxial with said cylindrical portion adapted to receive the cylindricalportion of the housing, a converging portion connecting said cylindricalportion and said aperture defining means and 12 at least one dependingrib formed on said converging portion disposed so as to engage thecylindrical portion of the next succeeding retention cup when positionedon the cylindrical portion of the separator housing so as to retain 5said cups in spaced apart relation thereon.

References Cited by the Examiner UNITED STATES PATENTS MARK NEWMAN,Primary Examiner.

HENRY F. RADUAZO, Examiner.

1. IN A GAS SEPARATOR FOR A SUBMERSIBLE WELL PUMP WHICH SEPARATORINCLUDES, A GAS SEPARATOR HOUSING DEFINING A RESERVOIR CHAMBER ANDADAPTED FOR DISPOSITION WITHIN A WELL IN OPERATIVE ASSOCIATION, WITH ASUBMERSED PUMP; MEANS WITHIN THE HOUSING DEFINING A PASSAGEWAY ADAPTEDTO PROVIDE FLUID COMMUNICATION BETWEEN THE RESERVOIR CHAMBER AND THEPUMP, AND MEANS DEFINING AT LEAST ONE INLET OPENING IN THE HOUSINGADAPTED TO PROVIDE FLUID COMMUNICATION BETWEEN THE WALL AND THERESERVOIR CHAMBER; MEANS DEFINING A RETENTION CHAMBER DISPOSED INOVERLYING RELATION TO SAID INLET OPENING, SAID CHAMBER DEFINING MEANSINCLUDING MEANS DEFINING AN INLET ADAPTED TO INITIALLY RECEIVE THE FLUIDFROM THE WELL, AND SAID RETENTION CHAMBER HAVING A FLUID RETAININGCAPACITY SUFFICIENT TO MOMENTARILY RETAIN WELL FLUID FLOWING FROM THEWELL TO THE RESERVOIR CHAMBER, SAID RETENTION CHAMBER DEFINING MEANSBEING DISPOSED SO AS TO PERMIT ENTRAINED GAS TO